The invention relates to a method for reconfiguring a cellular radio network connection. The reconfiguration particularly concerns a radio bearer providing a connection between a network part and a mobile station.
In the GSM system connection reconfiguration concerns the modifying of a call mode. The procedure is known as in-call modification. The term xe2x80x98modexe2x80x99 means the operational status of a call; it can be for instance a standard speech mode, data mode, fax mode, an alternating speech/data mode or an alternating speech/fax mode. When a connection is reconfigured, its mode can thus be changed e.g. from a speech mode to a data mode. In case the channel used for the connection does not support the required characteristics, channel configuration can be changed. The solution known from the GSM system is not, however, applicable for use in UMTS (Universal Mobile Telephone System) described below. The reason for this is that in the UMTS a single connection can simultaneously use one or more radio bearers. The characteristics of the radio bearers may have to be modified upon establishment of or during a connection.
The term xe2x80x98radio bearerxe2x80x99 refers to a service provided by a network layer. Multimedia service typically uses a plural number of radio bearers simultaneously for providing a service. Video telephony, for example, may require four different radio bearers: transmission of speech and image both use separate radio bearers for uplink and downlink. A multimedia service, such as video telephony, can also be implemented by using only one radio bearer per transmission direction, thereby avoiding the problem of synchronization between radio bearers of the same transmission direction. Radio bearer parameters comprise most of the first and second layer operational parameters. A radio bearer user, however, does not know the parameters of lower layers. Therefore the radio bearer user is not aware of how the radio bearer provides its services, i.e. whether it uses a half of a TDMA time slot, one time slot or a plural number of them, or one or more CDMA spreading codes.
A radio bearer is defined by a set of parameters or attributes that concern the traffic or quality characteristics of a service provided. A radio bearer is not to be considered similar to a logical channel, which is a service provided by a data link layer.
An object of the invention is therefore to provide a method and an equipment implementing the method in such a way that the above problems can be solved. This is achieved with the method described below, which is a method for reconfiguring a cellular radio network connection comprising a network part, the network part having a connection to a mobile station through at least one radio bearer. According to the method, a first party of the connection sends to a second party of the connection a radio bearer reconfiguration request message involving at least one radio bearer; the second party of the connection sends to the first party of the connection a reply message to the radio bearer reconfiguration request message.
The invention also relates to a cellular radio network comprising: a protocol software of a network layer of a network part, the software being arranged to have a connection to a mobile station through at least one radio bearer; a protocol software of a network layer of the mobile station, the software being arranged to have a connection to the network part through at least one radio bearer. The protocol software of the network layer of the network part is arranged to transmit to the protocol software of the network layer of the mobile station a radio bearer reconfiguration request message involving at least one radio bearer; the protocol software of the network layer of the mobile station is arranged to transmit to the protocol software of the network layer of the network part a reply message to the radio bearer reconfiguration request message.
The invention further relates to a cellular radio network comprising: a protocol software of a network layer of a network part, the software being arranged to have a connection to a mobile station through at least one radio bearer; a protocol software of a network layer of the mobile station, the software being arranged to have a connection to the network part by means of at least one radio bearer. The protocol software of the network layer of the mobile station is arranged to transmit to the protocol software of the network layer of the network part a radio bearer reconfiguration request message involving at least one radio bearer; the protocol software of the network layer of the network part is arranged to transmit to the protocol software of the network layer of the mobile station a reply message to the radio bearer reconfiguration request message.
The invention further relates to a method for reconfiguring a cellular radio network connection comprising a network part, the network part having a connection to a mobile station through at least one radio bearer. A first party of a connection transmits to a second party of the connection a radio bearer reconfiguration request message involving at least one radio bearer.
The preferred embodiments of the invention are disclosed in the dependent claims.
The invention is based on that either of the communicating parties can request, when needed, a radio bearer reconfiguration.
A method and system of the invention provide several advantages. The solution enables reconfiguration to be flexibly implemented in a system employing radio bearers. A plural number of radio bearers can be simultaneously reconfigured, the number of messages needed being thereby reduced, which in turn decreases the load on radio resources. When necessary, reconfiguration of radio bearers used for signalling can be carried out at connection set-up, thus avoiding a reallocation of signalling radio bearers that would perhaps otherwise be needed.